Apparatuses that facilitate growing plants in confined spaces provide means for persons who live in limited space arrangements, such as apartments, condominiums, and other similar urban environments, to enjoy the benefits of plant life. As plants grow, they produce by photosynthesis oxygen, which provides sustenance for humans, animals and other living organisms. Also, plant life serves as food for animals, humans and a wide variety of other creatures and organisms; and plant life can be used, processed, or otherwise modified to form a multiplicity of products. However, special challenges are presented when one attempts to grow plants in confined spaces. Recent interest in growing plants in apartments, home patios, and similar confined spaces has brought new emphasis on overcoming these challenges.
A variety of pots and trays for growing plants in restricted spaces are known in the art. For example, U.S. Pat. No. 3,106,801 discloses a tray for containing soil, a heating element for temperature control, and a transparent covering, all combined to constitute a portable greenhouse. However, the portable greenhouse does not contain a source of water for the plants grown therein. Adequate space for appropriate volumes of liquid nutrients necessary to plant growth is one of the major challenges to growing plants in confined spaces.
An additional challenge for growing plant in confined spaces is the strict timing requirements for providing liquid nutrients to the growing plants. A great variety of plant species have been grown in confined spaces. Species vary in the extent of care and attention required to maintain them in a healthy condition. The feeding of plants with necessary liquid nutrients requires repeated additions at intervals specific to the demands of each type plant. For successful growth of plant life, the supply of an appropriate amount of liquid nutrients during growth and the effective distribution of that liquid to the plant roots are essential. In the growing of plants, there is a need to provide liquid nutrients to the root system of a plant in a controlled manner, on a substantially continuous basis, and in correct amounts. This allows the particular plant to feed itself as needed, without the damaging effects of over-watering. The most significant problem in tending to potted plants is watering and feeding them. Generally, a caretaker must tend to each potted plant individually, determining when and how much water and food to provide to each plant. Plants of different types may require different amounts of water or water at different intervals. Whether of the same or a different type, plants located in sunny versus shaded areas or located in different types or sizes of pots may all have different water requirements. Thus, a caretaker may need to tend various plants on an everyday basis, watering and/or feeding different plants on different days. These requirements would thus limit persons who wanted to leave their potted plants in their home or apartment for a period of time, such as for a vacation. Such persons would have to find another party to tend to the plants.
Conventionally, watering plants is accomplished by pouring water from above onto the plant and surrounding soil. Using this method, such watering must be done at regular intervals to maintain the health of a plant being grown, and those intervals are determined by the type of plant being grown and other environmental considerations. Too little water and too much water at particular time intervals of a plant's growth cycle can each be detrimental to a plant's growth and health. Typically, a conventional planting pot includes a floor having a centrally located aperture, which serves as a drain hole when the plant has been over watered. Draining through the bottom of the pot is wasteful and can be a nuisance, such as when water drains from the deck of an upper apartment to an apartment below. It is typical for such a planting pot to be placed on the interior of a larger outer container or pot to contain excess watering liquid that the potting soil cannot contain. The result from this configuration sometimes leads to an over-watering which can virtually drown and kill the plant, or result in root rot, which will have the same effect due to water accumulating in the container or pot. Such conventional watering methods often require daily attention to check soil moisture and water as needed. It is also common for under and over-watering to occur when the plants are not checked often enough.
Bottom watering (also called self-watering) is an alternative method for providing sufficient liquid nutrients during plant growth that aims to avoid the disadvantages associated with conventional watering techniques. Bottom watering is accomplished by placing water at or around the bottom of a plant container (in some form of container for the water) in limited contact with the soil of the plant container in such a manner that facilitates water penetration into the soil but also prevents the soil from being washed out of the plant container. Self-watering systems for plant growth require a source providing water to the plant container, they require a mechanism for distributing water from the water source to the plant roots; and they require that such water source provide only the volume of water needed by the plant. Often, self-watering systems rely on migration of the water into the soil by means of a wick that facilitates capillary migration of the water from its container through the wick and into the soil in the plant container. Adhesion of the particles of water to the particles of the wick produces capillary migration of the water from its container through the wick and into the soil.
Self-watering plant containers are known to offer several advantages over conventional plant containers that require top watering. For example, with bottom watering there is less water lost to the surrounding air due to evaporation than occurs in conventional watering. Therefore less water is required to maintain the desired soil moisture levels in the soil. Also, with bottom watering there is less run-off of fertilizers and other soil treatments relative to top watering, resulting in a greater retention of fertilizers and other treatments. Additionally, self-watering plant containers give growers more flexibility in scheduling the addition of water to a bottom container than the grower would have with conventionally watered plant containers. With conventional plant containers watered from the top, the moisture content of the soil in the plant container will be higher immediately after water is added, and it will gradually reduce as the plant absorbs liquid nutrients from the soil. In these circumstances, a grower must closely monitor the moisture content of the soil in the plant container and carefully time the additions of water. Water added at too often may result in over-watering, while water added too seldom may result in under-watering. By comparison, reservoirs in self-watering containers provide a steady source of moisture to the soil in the container. The reservoir thus frees growers from the stricture of such close observation of the moisture of the soil in the plant container, thereby giving growers more flexibility in the timing of adding water to the reservoir vis-a-vis pouring water on top of the plant and surrounding soil at more time-sensitive intervals.
Various systems have been proposed to allow bottom watering of plants grown in confined spaces. For example, U.S. Pat. No. 4,117,632 discloses a self-watering system for a potted plant that includes a small liquid container fitted below and connected to a plant container. An insert is provided with a wick for transporting liquid from the liquid container up into the lower part of the plant container. The wick extends from the liquid container through the insert into the plant container and is then wound around the upper part of the insert (surrounded by soil inside the plant container), thus providing a long transport path for capillary-migration of water from the liquid container into the surrounding soil in the plant container.
U.S. Pat. No. 3,534,498 discloses a self-watering system for a potted plant that includes a plant container concentrically fitted inside a larger container. The larger container houses two separate liquid reservoirs, a lower reservoir in the bottom area of the larger container and an upper reservoir placed in the circumferential space between the walls of the two containers near the top of the two containers. The plant container is connected to the lower reservoir via holes in the plant container, and a wick provides capillary migration of water from the lower reservoir into the plant container. The upper reservoir is connected to the lower reservoir by means of a connecting tube. When the water level in the lower reservoir drops below the lower end of the connecting tube, water flows under gravity from the upper reservoir into the lower reservoir, as water in the upper reservoir is displaced by air until the water level in the lower reservoir rises to cover the end of the connecting tube. At that point, atmospheric pressure on the surface of the water in the lower reservoir holds up the column of water in the connecting tube and prevents further flow from the upper reservoir.
U.S. Pat. No. 6,622,425 provides yet a third example. It discloses a portable greenhouse having a tub (or pan) sized to contain several plant containers and further suited to hold some water in the tub beneath the plant containers. The volume of water held by the tub is relatively small and limited by portability considerations.
There exists a need for a portable greenhouse that includes a self-watering system that can overcome the problems of the currently known self-watering systems, and further includes a self-contained reservoir of sufficient size to provide a source of water to self-water the plants in the greenhouse for an extended period.